TM 9-4940-568-34
5-131
d.
Testing Exciter Rotor.
(1)
Testing Winding Resistance: Disconnect the six rotor winding leads from the terminal posts on the
rectifier assembly. With a Wheatstone bridge, measure electrical resistance across each pair of rotor
windings: U (CR1 or CR4) and V (CR2 or CR5), V (CR2 or CR5) and W (CR3 or CR6), W (CR3 or
CR6) and U (CR1 or CR4). See the winding schematic. Replace the whole rotor shaft assembly (Para
5-21) if the resistance of any winding is not as specified in Table 5-1.
(2)
Testing Winding Insulation Resistance: Using an ohmmeter, measure the resistance between any rotor
winding lead or the terminal to which it is connected and the rotor laminations. Replace the whole rotor
shaft assembly (Para 5-21) if insulation resistance is less than 1 megohm.
